Germany knew the French would do anything to avenge their defeat in 1871 (and they were right); both they & the French knew France couldn’t do it alone, and France drew England into an alliance that also served England’s end of pressuring Germany’s colonial gains (and the navy it was building to protect it). Germany had the least cause to fight in, and the most to lose from, fighting in WWI - both England & France had larger empires than them, and Britain had a navy that dominated the world. The German High Command was simply reacting to the reality of that.
Holland was neutral (and not invaded), and I’d never heard of anything “brutal” in the occupation of Belgium. Poland didn’t exist at the start of the war; it’s territory was divided between Germany, Austria-Hungary, and Russia. This part sounds like the second war.
The Central Powers were foiled only be the American entry into the war; Russia had surrendered, and France & Italy were on the brink. The U-boat campaign was effective enough to win, and Wilson knew it.
Germany had the most to gain from fighting the British and French; what could France and Britain and gained from a land war in Europe, since the colonies were increasingly the field of economic competition? Germany had pursued colonial possessions for decades but had failed to capture much that was useful. Germany, as it constantly complained, was “land locked,” and “encircled.” It had “no choice” but to “attack first.” This is well-established German rhetoric. And it’s just the first example in a long line of such complaints - Hitler’s Sudeten Germans, the unreasonableness of the Poles, the Soviets’ insistence that the “bourgois imperialists” were “endangering the revolution,” and so on, down to the Islamists’ ridiculous claims today. The Germans, in fact, complained that its 80 millions were forced to live inside German borders, when it was clearly going to be much larger than France (so it said) and deserved something like “lebensraum,” particularly in Polish-Ukrainian territory.
The Kaiser’s courting of the Ottomans, particularly via the Berlin-Baghdad railway, as well as training the Turks’ modern army, began decades before World War 1 began. For an account of the Kaiser’s ostentatious visit to Ottoman Palestine, see the book Jerusalm 1913 - he sought to become the protector of the Muslims and made gestures about jihad to them (even as he made promises to the Jews there and in Germany).
It is also well-known that Britain had only a very small expeditionary force; it had nothing like the mammoth land army of the Kaiser or the strategic reserves of the Tsar. France did have a rather large army, but it was distracted by political crisis after political crisis. It was in no mood to simply attack Germany, which by then had clearly surpassed it in terms of economic and man power.
The Belgian atrocities of the Germans were the first propaganda opportunity for Britain and France, aside from the invasion of neutral Belgium itself. They burned down some library or other and were appalled that Belgians would resist, so they adopted terror tactics in limited cases. These of course were played up for all their worth by France and Britain.
I think this game of “who benefits?” is dangerous and not really that helpful. This also leads people to conclusions about “international banking” that make them sound like Lenin in his inaugural address upon the creation of the Comintern, among others.
Russia was teetering on the verge of ungovernability since 1905, a decade prior to the war, and was busy in its great game.
So in fact, according to the correlation of forces, Germany was pretty much the only power that had a real interest in starting a land war in Europe that it believed it could win.